Objective To construct a culture system of endometrial organoids for infertility induced by non-immune or immune factors,and to compare the immune cytokines between them.Methods The samples were collected from infertility patients undergoing hysteroscopy in Department of Reproductive Medicine Center of The First Affiliated Hospital of Naval Medical University(Second Military Medical University).Endometrial tissues were obtained from patients with infertility caused by non-immune factors(n=3)and patients with repeated implantation failure(RIF)(n=5).The tissues were embedded in matrix glue for 3D culture after washing,digestion,re-suspension and plate attachment.The growth of endometrial organoids of the 2 groups was observed under inverted microscope;the expression of estrogen receptor,keratin and E-cadherin,which were specific endometrial markers,was detected by immunofluorescence staining;and the cytokines of the 2 groups were determined by enzyme-linked immunosorbent assay(ELISA)and the differences of cytokines between the 2 groups were observed.Results During the process of in vitro culture of endometrial organoids,the volume of organoids and the number of cells gradually increased.After 7-10 d of culture,the volume of organoids reached a stable state,and the shape gradually became a perfect circle.At the same time,the number of organoids from the infertility patients caused by non-immune factors was more than that from the infertility patients caused by RIF.Immunofluorescence staining showed the expression of endometrial related marker proteins estrogen receptor,keratin and E-cadherin,indicating the successful construction of endometrial organoids.ELISA results showed that the levels of interferon(IFN)-γ,interleukin(IL)-10,tumor necrosis factor(TNF)-α,IL-4 and TNF-α/IL-4 ratio between the 2 groups were significantly different(P＜0.05 or P＜0.01).There were no significant differences in the levels of TGF-β1 or IL-17,the ratios of IL-17/TGF-β1,IFN-γ/IL-10 or TNF-α/IL-10(all P＞0.05).Conclusion Endometrial organoids with proliferative ability from patients with non-immune infertility and RIF have been successfully cultured in vitro,which provides a new model for the basic research of immune infertility.